青少年要养成下列哪些良好生活习惯（　　）

①不吸烟②心态平和③偶尔吸食毒品④常喝酒⑤坚持体育锻炼⑥不吃街边地摊烧烤．

设$m\in R$,命题“若$m>0$,则方程$x^2+x-m=0$有实根”的逆否命题是(   )

    “How can I learn English well?” “This is a 1 many students may ask. In my opinion, the most effective(有效的) 2 is to learn lessons by heart. If you can recite the text and write it out, you will learn it pretty well. And if you can tell 3 your own words about 4 the lesson says, you are a very successful learner indeed. Your English will be quite perfect.

    This is a difficult task. However, if you try to learn by heart only part of each lesson, you'll find it not so hard 5 you might have thought.

    Learn this way, and you will 6 fast progress. Of course, writing is also necessary. It helps you a lot on your way to 7 in English studies.

    It's equally(同样地) important to feel the language. You should laugh at English jokes and be 8 at bad news. When using English, try to 9 your mother tongue(母语). 10 helping you, your own language gets in your way. So, never try to learn English through putting every word into Chinese.